Sunflower yield and climatic variables

SUMMARY A group of hybrids with higher oil yield was selected from the comparative yield trials carried out in the EEA Pergamino, during seasons 2004-2005, 2005-2006 and 2006-07. The objective was to study the associations between seed yield, oil content, oil yield and climatic variables obtained from two methods: stepwise and principal component analysis. Both methods arrived at similar results confirming the associations between yield and climatic variables. Positive correlation between seed yield and thermal amplitude was obtained in sowing- flowering, as well as between oil yield and thermal amplitude in flowering- maturity. The seed yield was negatively correlated with the hours of sunlight (heliophany) and rainfall in sowing-flowering. The oil content was positively correlated with the hours of sunlight (heliophany) in flowering- maturity and with thermal amplitude in flowering maturity. As the variations of climatic variables have a substantial importance in determining yield, the selection of stable genotypes would be an important contribution to sunflower breeding.